Protection of glass panes in buildings during storms has been a great problem in the past, and many efforts have been made to prevent the glass panes from shattering and falling into the building due to high winds, projectiles and debris thereby damaging the interior of the building due to the glass and due to wind and rain damage through the breached glass pane. Prior art attempts to protect glass panes in buildings from storm damage have included prefabricated storm shutters, plywood sheets, lamination systems and taping. Storm shutters are normally made of aluminum or other lightweight metal alloys, fiberglass, acrylate or other plastic. Storm shutters are fabricated to fit the exact measurements of window structures, including glass panes, to be protected and have the disadvantages of being expensive and requiring substantial time for fabrication such that storm shutters are not available unless ordered well in advance of a storm. Plywood sheets are generally sold in four-foot by eight-foot sheets with a thickness of ⅝ inch such that the plywood sheets weight approximately 50 pounds each. The plywood sheets must be cut to fit the size of the window structures and are normally drilled and screwed into the building or window frame requiring craftsmanship, labor and hardware and, thus, having the disadvantages of being expensive and requiring substantial time to cover windows when a storm is approaching as well as of being extremely heavy. Lamination systems, such as those supplied by 3M Corporation (e.g. Scotchshield) have the disadvantages that they are films applied to the interior of the glass panes in that they are designed to prevent shattered glass from collapsing to thereby prevent rain damage and glass fragments from becoming projectiles. The film is not particularly effective in preventing the glass from shattering and does not make the glass more shatter resistant. Since the film is on the interior of the glass, it cannot absorb enough energy from the glass fast enough to prevent a failure or fracture of the glass if the glass pane is struck by debris or projectiles. Accordingly, the primary use of lamination systems is to prevent shattered glass from falling apart. Taping of windows results, at best, in the holding of most of a fractured glass pane in place to reduce rain damage and the risk of individuals being cut.
U.S. Pat. No. 3,830,670 to Bengston and No. 4,596,725 to Kluth et al are exemplary of polyurethane foams and discuss one-component and two-component polyurethanes. U.S. Pat. No. 3,455,865 to Bolt et al, No. 3,486,918 to Motter, No. 4,636,543 to Helton, No. 5,020,288 to Swenson, No. 5,107,643 to Swenson, No. 5,143,949 to Grogan et al, No. 5,186,978 to Woodhall et al, No. 5,281,436 to Swidler, No. 5,302,413 to Woodhall et al, No. 5,362,786 to Woodhall et al, No. 5,411,760 to Woodhall et al and No. 5,523,117 to Woodhall et al, are representative of polymeric films or layers for glass and/or polymeric films or layers removable by peeling. None of the above patents disclose or contemplate the use of a polymeric foam to protect a glass pane of a window structure installed in a building for protection against damage from storms.
From the above, it will be appreciated that there is a great need for protection of glass panes in window structures installed in buildings due to storms where the protection can be quickly applied and is inexpensive while also being easily removed.
Accordingly, it is an object of the present invention to provide protection for glass panes overcoming the abovementioned disadvantages of the prior art.
Another object of the present invention is to protect glass panes in buildings from storm damage by temporarily applying or adhering a polymeric foam layer on the glass pane and, after the storm passes, removing the polymeric foam layer by peeling or stripping the layer from the glass pane.
A further object of the present invention is to apply a polyurethane foam layer to a glass pane of a window structure in a building to absorb energy from debris during a storm and to maintain the integrity of the glass pane in the event of damage thereto.
Another object of the present invention is to adhere a polyurethane foam layer to the outside surface of a glass pane to produce a temporarily protected window structure in a building.
Some of the advantages of the present invention over the prior art are that the polymeric foam layer protects glass panes from shattering in wind storms, is easy to apply, and can be applied by spraying in substantially less time than required for other glass pane protection systems with no measuring required, containers for the compositions of the polymeric foam layer can be small, the weight of the polymeric foam layer is insubstantial, the polymeric foam layer can be easily removed by peeling from the exterior window structure surface either from the exterior of the building or, if the windows can be opened, from the interior of the building, a two-component polyurethane system provides long shelf life such that an individual can be prepared at all times, the polymeric foam layer can be installed by one person, is translucent to let light in and will not lose its shape or protective qualities when wet by rain.
The present invention is generally characterized in a method of protecting a glass pane installed in a building from damage during a storm comprising the steps of before the storm arrives, applying a polymeric foam layer to the exterior of the glass pane and, after the storm has passed, peeling the polymeric foam layer from the glass pane. Preferably, the polymeric foam layer is a polyurethane foam having cells absorbing energy from wind-borne debris, wind and driven rain. The present invention is further generally characterized in a window structure installed in a building comprising a glass pane having an exterior surface, a frame mounting the glass pane to the buildings and a layer of polyurethane foam disposed on the exterior surface of the glass pane for protecting the glass pane from storm damage, the layer of polyurethane foam being peelable for removal from the glass pane.
Other objects and advantages of the present invention will become apparent from the following description of the preferred embodiments taken in conjunction with the accompanying drawings wherein like parts in each of the several figures are identified by the same reference characters.